The invention relates to an apparatus for decanting pulverulent product into a receptacle made of deformable material—in particular into a bag—which receptacle or bag is arranged in a container made of rigid material and is temporarily placed upstream of a lock system containing so-called glove boxes, according to the preamble of Patent Claim 1. The invention moreover relates to a method which can be carried out using said apparatus.
Various systems are known which can be used to empty toxic powder out of drums equipped with plastic bags, in such a way that there is little contamination. One of the most common methods is the use of isolation systems. The drum is introduced into the isolator through a lock, lifted by a mechanical device, and then the plastic bag filled with the product is opened by an operator using gloves. The product is then emptied manually into a funnel which is connected to the lower part of the isolator. The disadvantage of these isolation systems is that they are designed for specific applications and therefore have only a very small degree of flexibility. The space requirement and investment costs of such systems are considerable. Moreover, a considerable amount of dust is produced within the isolator, so that the filters rapidly become blocked, the system has to be cleaned frequently and there is a risk that product will be lost.
There is also a system which contains a transparent cylindrical glove box, as it is known, with side openings for gloves. A stainless steel ring with a flat seal is fixed to the lower part of the glove box and provides a seal with respect to the drum. A movable suction lance is introduced from above, which suction lance is connected to the glove box through a sealing sleeve. The system is connected to a pneumatic lifting device which allows the glove box to be raised and lowered above the drum. The drum is emptied by an operator with the aid of the suction lance, which is connected to a pneumatic conveyor system. The powder is conveyed under vacuum and emptied in a completely closed manner into the containers which are to be filled.
Compared to a conventional isolator, the advantages of such a system are a small space requirement and reduced investment costs. Depending on the type of product, however, the use of the suction lance may prove to be taxing and time-consuming. Moreover, it is sometimes difficult to completely empty the plastic bag. Furthermore, the system cannot be used for products which contain lumps. When emptying a large number of drums (>10 drums), the emptying time for a unit of product may prove to be very long and unsatisfactory (10–15 min/drum).
In view of this, the inventor set himself the aim of eliminating the recognized problems. In particular, it is to be possible for drums equipped with plastic bags which contain toxic powder to be emptied virtually without any contamination (<1 μg/m3) and in a semi-automatic manner.